As used herein, the term “segregated quantum structure” shall be understood to mean an isolated mass of material capable of holding an extra carrier. Typically, a segregated quantum structure of the present invention will be encased in a shell of processed semiconductor material in all three dimensions.
Further, the term “quantum dot” as used herein is synonymous with the term “segregated quantum structure” as used herein.
As used herein, the term “quantum well” shall be understood to mean a precursor configuration of unprocessed materials, which when processed will give rise to the formation of segregated quantum structures. Typically, a quantum well of the present invention will provide carrier confinement in only one dimension when processed. The term “thinned quantum well” shall be understood to mean the precursor configuration of processed materials prior to re-processing.
The present invention includes: methods for forming quantum tunneling devices, various quantum tunneling devices and various electronic devices.
A preferred method of the present invention for forming quantum tunneling devices comprises the steps of: (1) providing a quantum well, the quantum well comprises a composite material, the composite material comprises at least a first and a second material; and (2) processing the quantum well so as to form at least one segregated quantum tunneling structure encased within a shell comprised of a material arising from processing the composite material, wherein each segregated quantum structure is substantially comprised of the first material.
While the composite material may comprise any suitable mixture, doped mixture, or blend of at least tow materials, it is generally preferred that the composite material comprise a material selected from the group consisting of: composites comprising silicon, composites comprising germanium, composite comprising carbon, a silicon-germanium composite, a silicon-carbon composite, a germanium-carbon composite, a silicon-tin composite, a silicon-germanium-carbon composite, a silicon-germanium-carbon-tin composite, a gallium-arsenic composite, an indium-arsenic composite, an aluminum-arsenic composite, an aluminum-gallium-arsenic composite, an indium-gallium-arsenic composite, an indium-phosphorus composite, an indium-antimony composite, a gallium-antimony composite, an aluminum-antimony composite, an indium-gallium-antimony composite, a gallium-aluminum-antimony composite, an indium-gallium-antimony composite, a gallium-aluminum-antimony composite, an indium-aluminum-antimony composite, an indium-gallium-aluminum-antimony composite, an indium-nitrogen composite, a gallium-nitrogen composite, an aluminum-nitrogen composite, an indium-gallium-nitrogen composite, a gallium-aluminum-nitrogen composite, an indium-gallium-aluminum-nitrogen composite, an indium-gallium-arsenic-nitrogen composite, a zinc-sulfur composite, a zinc-selenium composite, a zinc-tellurium composite, a cadmium-sulfur composite, a cadmium-tellurium composite, a mercury-sulfur composite, a mercury-selenium composite, a mercury-tellurium composite, a mercury-cadmium-tellurium composite, and mixtures thereof.
It is further preferred that at least a portion of the shell is sufficiently thin enough to permit quantum tunneling of electrons from a first segregated quantum structure to a second structure selected from the group consisting of segregated quantum structures and electrodes. In order to ensure that the shell is sufficiently thin enough to permit quantum tunneling, it is preferred that the shell is reduced in thickness after processing.
While any appropriate processing method may be used to create the segregated quantum structure, the preferred methods include oxidation, reduction, and nitridation. An appropriate processing method is a processing method in which one of the materials undergoes a preferential reaction wherein that material has a faster reaction rate than the other materials. It is preferred that an appropriate processing method be self-limiting. It is further preferred that an appropriate processing method cause the migration of at least one of the materials into segregated quantum structures while transforming at least some of the remaining materials into a shell of a material arising from the process.
It is preferred that the segregated quantum structure has no dimension greater than about 500 nanometers.
In order to control uniformity in quantum tunneling devices of the present invention, it is preferred to apply a mask to the quantum well. Further, it is additionally preferred to remove at least a portion of the material arising from processing the composite material from the shell thereby thinning the shell and forming a thinned quantum well. It is even more preferred to re-process the thinned quantum well. It is preferred that the re-processing is accomplished by a process selected from the group consisting of: oxidation, reduction, and nitridation.
It is preferred that each segregated quantum structure is separated from each other segregated quantum structure by material arising from the processing of the composite material.
A preferred quantum tunneling device of the present invention is formed in accordance with the method described above.
A second method of the present invention for forming quantum tunneling devices comprises: (1) providing a quantum well comprising at least three layers, each of the at least three layers comprising a first material, wherein at least one of the at least three layers additionally comprises at least a second material and (2) processing the quantum well so as to form at least one segregated quantum structure comprising at least the second material encased in a material arising from processing the first material.
It is preferred that each layer comprising the second material is disposed between at least two layers not comprising the second material.
It is preferred that the first materials is selected from the group consisting of silicon, germanium, carbon, tin, gallium, arsenic, indium, aluminum, boron, phosphorus, antimony, nitrogen, zinc, sulfur, selenium, tellurium, cadmium, mercury, lead, and mixtures thereof. Additionally, it is preferred that the first material comprises a component selected from the group consisting of elements of group IIA of the periodic table, elements of group IIIA of the periodic table, elements of group IVA of the periodic table, elements of group VA of the periodic table, elements of group VIA of the periodic table, and mixtures thereof.
It is preferred that the second material is selected from the group consisting of silicon, germanium, carbon, tin, gallium, arsenic, aluminum, indium, boron, phosphorus, antimony, nitrogen, zinc, sulfur, selenium, tellurium, cadmium, mercury, lead, and mixtures thereof. Additionally, it is preferred that the second material is selected from the group consisting of elements of group IIA of the periodic table, elements of group IIIA of the periodic table, elements of group IVA of the periodic table, elements of group VA of the periodic table, elements of group VIA of the periodic table, and mixtures thereof.
Although any appropriate processing means may be used to process the quantum well, it is preferred that the processing is accomplished by a process selected from the group consisting of oxidation, reduction, and nitridation.
It is preferred that at least a portion of the first material encasing the at least one segregated quantum structure is sufficiently thin enough to permit quantum tunneling of electrons from a first segregated quantum structure to a second structure selected from the group consisting of segregated quantum structures and electrodes.
A preferred quantum tunneling device of the present invention is formed in accordance with the methods described above.
Yet another method of the present invention for forming quantum tunneling devices, comprises the steps of: (1) growing a quantum well on a substrate, the quantum well comprises at least a first material and a second material; (2) patterning a mask on said quantum well; (3) etching the quantum well so as to form a pillar; and (4) processing the pillar so as to convert the first material thereby forming an altered first material and causing the second material to form at least one segregated quantum structure embedded in the altered first material.
It is preferred that the method additionally comprise the steps of: (1) etching the altered first material so as to form a re-etched pillar; and (2) subjecting the re-etched pillar to a process so as to further alter the re-etched pillar.
It is preferred that the quantum well comprises at least three layers each of which comprises a first material, wherein at least one said layer further comprises a second material.
It is even more preferred that each layer comprising a second material is disposed between at least two layers substantially not comprising the second material.
It is preferred that the substrate comprises a material selected from the group consisting of silicon, germanium, a silicon-carbon mixture, an indium-arsenic mixture, a gallium-arsenic mixture, an aluminum-arsenic mixture, an indium-phosphorus mixture, a gallium-phosphorus mixture, an aluminum-phosphorus mixture, an indium-antimony mixture, an aluminum-antimony mixture, an indium-nitrogen mixture, a gallium-nitrogen mixture, an aluminum-nitrogen mixture, an indium-arsenic mixture, a gallium-antimony mixture, sapphire, alumina, diamond, and mixtures thereof.
It is preferred that the first material is selected from the group consisting of silicon, germanium, carbon, tin, gallium, arsenic, indium, aluminum, phosphorus, boron, antimony, nitrogen, zinc, sulfur, selenium, tellurium, cadmium, mercury, lead, and mixtures thereof. Alternatively, it is preferred that the first material is selected from the group consisting of elements of group IIA of the periodic table, elements of group IIIA of the periodic table, elements of group IVA of the periodic table, elements of group VA of the periodic table, elements of group VIA of the periodic table, and mixtures thereof.
It is preferred that the second material is selected from the group consisting of silicon, germanium, carbon, tin, gallium, arsenic, indium, aluminum, phosphorus, boron, antimony, nitrogen, zinc, sulfur, selenium, tellurium, cadmium, mercury, lead, and mixtures thereof.
It is preferred that the mask is patterned by a process selected from the group consisting of electron-beam lithography, contact lithography, projection lithography, self-assembly through modification by wetting and de-wetting, and nano-imprinting. Further, it is preferred that the mask comprises a material selected from the group consisting of silicon, silicon dioxide, silicon nitride, titanium, gold, platinum, nickel, chromium, aluminum, silver, tantalum, molybdenum and mixtures thereof. It is more preferred that the mask is a photoresist. Although the mask may be of any desired size, it is preferred that the mask has a diameter in the range of about 0.5 nanometers to about 500 nanometers.
It is preferred that the quantum well is etched by a process selected from the group consisting of plasma etching, wet etching with acidic solutions, wet etching with basic solution, anisotropic etching, isotropic etching, barrel etching, reactive ion etching, electron resonance reactive ion etching, and inductively coupled plasma reactive ion etching.
It is preferred that the pillar has a diameter in the range of about 0.5 nanometers to about 500 nanometers.
It is preferred that each of the at least one segregated quantum structures has a diameter of less than about 500 nanometers. It is even more preferred that each of the at least one segregated quantum tunneling structures is substantially crystalline.
It is preferred that the altered first material is etched by a process selected from the group consisting of plasma etching, wet etching with acidic solutions, wet etching with basic solution, anisotropic etching, isotropic etching, barrel etching, reactive ion etching, electron cyclotron resonance reactive ion etching, and inductively coupled plasma reactive ion etching.
It is preferred that the re-etched pillar has a diameter less than the diameter of the pillar.
Preferred quantum tunneling devices of the present invention are formed in accordance with the method described above.
A quantum tunneling device of the present invention comprises: (1) at least one segregated quantum structure; and (2) a casing of a first material encapsulating the at least one segregated quantum structure, wherein the casing is sufficiently thin so as to permit quantum tunneling of electrons from a first segregated quantum structure so a structure selected from the group consisting of segregated quantum structure and electrodes.
It is preferred that the at least one segregated quantum structure has a diameter of less than about 200 nanometers. It is more preferred that the at least one segregated quantum tunneling structure has a diameter of less than about 50 nanometers.
It is preferred that the segregated quantum structure comprises a material selected from the group consisting of silicon, germanium, carbon, tin, gallium, arsenic, indium, aluminum, phosphorus, boron, antimony, nitrogen, zinc, sulfur, selenium, tellurium, cadmium, mercury, lead, and mixtures thereof.
It is preferred that the first material comprises a material selected from the group consisting of silicon, germanium, carbon, tin, gallium, arsenic, indium, aluminum, phosphorus, antimony, nitrogen, zinc, sulfur, selenium, tellurium, cadmium, mercury, and mixtures thereof. Alternatively, it is preferred that the first material comprises a semi-conductive material selected from the group consisting of elements of group IIA of the periodic table, elements of group IIIA of the periodic table, elements of group IVA of the periodic table, elements of group VA of the periodic table, elements of group VIA of the periodic table, and mixtures thereof.
It is preferred that the first material has been altered by a process selected from the group consisting of oxidation, reduction, and nitridation.
It is preferred that the quantum tunneling device has not dimension greater than 500 nanometers.
It is preferred that the casing is substantially non-crystalline. It is further preferred that the at least one segregated quantum structure is substantially crystalline.
It is preferred in quantum tunneling devices having at least two segregated quantum structures, the at least two segregated quantum structures are substantially aligned along an axis so as to form a segregated quantum tunneling wire.
An electronic device of the present invention comprises: (1) a quantum tunneling device, the quantum tunneling device comprises at least one segregated quantum structure and a casing of a first material encapsulating the at least one segregated quantum structure; and (2) at least one electrode, wherein the casing is sufficiently thin so as to permit quantum tunneling of electrons from a segregated quantum structure to the at least one said electrode.
It is preferred that each segregated quantum structure has a diameter less than about 200 nanometers. It is more preferred that each segregated quantum structure has a diameter less than about 100 nanometers. It is most preferred that each segregated quantum structure has a diameter of not exceeding about 25 nanometers.
It is preferred that the segregated quantum structure comprises a material selected from the group consisting of silicon, germanium, carbon, tin, gallium, arsenic, indium, aluminum, phosphorus, boron, antimony, nitrogen, zinc, sulfur, selenium, tellurium, cadmium, mercury, lead, and mixtures thereof.
It is preferred that the first material comprises a material selected from the group consisting of silicon, germanium, carbon, tin, gallium, arsenic, indium, aluminum, phosphorus, boron, antimony, nitrogen, zinc, sulfur, selenium, tellurium, cadmium, mercury, lead, and mixtures thereof. Alternatively, it is preferred that the first material comprises a semi-conductive material selected from the group consisting of elements of group IIA of the periodic table, elements of group IIIA of the periodic table, elements of group IVA of the periodic table, elements of the group VA of the periodic table, elements of group VIA of the periodic table, and mixtures thereof.
It is preferred that the first material has been altered by a process selected from the group consisting of oxidation, reduction, and nitridation.
It is preferred that the at least one electrode comprises a material selected from the group consisting of lithium, beryllium, boron, carbon, nitrogen, oxygen, aluminum, silicon, calcium, titanium, vanadium, manganese, iron, cobalt, nickel, copper, zinc, gallium, germanium, arsenic, yttrium, zirconium, niobium, molybdenum, palladium, silver, cadmium, indium, tin, antimony, barium, tantalum, tungsten, iridium, platinum, gold, mercury, thallium, lead, bismuth, and mixtures thereof.
It is preferred that the segregated quantum structure is substantially crystalline. It is further preferred that the casing is substantially non-crystalline.
It is preferred that the electronic device is operational at temperatures in excess of about 1 K. It is more preferred that the electronic device is operational at temperatures in excess of about 200 K.
In electronic devices comprising at least two segregated quantum structures, it is preferred that each segmented quantum structure is encapsulated in a casing of the first material and that each segregated quantum structure is separated from each other segregated quantum structure by a sufficiently thin layer of a first material so as to permit quantum tunneling of electrons from a given segregated quantum structure to at least one other segregated quantum structure.
It is further preferred that the at least two segregated quantum structures are substantially aligned along an axis so as to form a segregated quantum tunneling wire.
A quantum-dot cellular automate node switch of the present invention comprises: (1) at least two quantum tunneling devices, each quantum tunneling device comprising: (a) at least one segregated quantum structure and (b) a casing of a first material encapsulating the at least one segregated quantum structure, wherein each quantum tunneling device is adjacent to at least one other quantum tunneling device such that at least one segregated quantum structure in a first quantum tunneling device is separated by a distance from at least one segregated quantum structure in a second quantum tunneling device, and wherein the distance is sufficiently small so as to permit coulombic interaction between electrons from at least one segregated quantum structure in the first quantum tunneling device and at least one segregated quantum structure in the second quantum tunneling device; and (2) at least two electrodes, each electrode separated from a segregated quantum structure by a distance, wherein the distance is sufficiently small so as to permit coulombic interaction between electrons of the segregated quantum tunneling structure and the electrode.
It is preferred that each segregated quantum structure has a diameter less than about 200 nanometers. It is more preferred that each segregated quantum structure has a diameter less than about 50 nanometers. It is most preferred that each segregated quantum structure has a diameter not exceeding about 10 nanometers.
It is preferred that the segregated quantum structure comprises a material selected from the group consisting of silicon, germanium, carbon, tin, gallium, arsenic, indium, aluminum, phosphorus, boron, antimony, nitrogen, zinc, sulfur, selenium, tellurium, cadmium, mercury, lead, and mixtures thereof.
It is preferred that the first material comprises a material selected from the group consisting of silicon, germanium, carbon, tin, gallium, arsenic, indium, phosphorus, boron, antimony, aluminum, nitrogen, zinc, sulfur, selenium, tellurium, cadmium, mercury, lead, and mixtures thereof. Alternatively, it is preferred that the first material comprises a semi-conductive material selected from the group consisting of elements of group IIA of the periodic table, elements of group IIIA of the periodic table, elements of group IVA of the periodic table, elements of group VA of the periodic table, elements of group VIA of the periodic table, and mixtures thereof.
It is preferred that the first material has been altered by a process selected from the group consisting of oxidation, reduction, and nitridation.
It is preferred that each at least one electrode comprises a material selected from the group consisting of lithium, beryllium, boron, carbon, nitrogen, oxygen, aluminum, silicon, calcium, titanium, vanadium, manganese, iron, cobalt, nickel, copper, zinc, gallium, germanium, arsenic, yttrium, zirconium, niobium, molybdenum, palladium, silver, cadmium, indium, tin, antimony, barium, tantalum, tungsten, iridium, platinum, gold, mercury, thallium, lead, bismuth, and mixtures thereof.
It is preferred that at least one of the at least two segregated quantum structures is substantially crystalline. It is further preferred that the casing is substantially non-crystalline.
It is preferred that the quantum-dot cellular automata node switch of the present invention is operational at temperatures in excess of about 2 K. It is even more preferred that the quantum-dot cellular automata node switch is operational at temperatures in excess of about 200 K.
Another quantum-dot cellular automata node switch of the present invention comprises: (1) a quantum tunneling device, the quantum tunneling device comprises (a) a casing of a first material and (b) at least two segregated quantum structures, wherein each segregated quantum structure is encapsulated in a casing of the first material, and wherein each segregated quantum structure is separated from each other segregated quantum structure by a sufficiently thin layer of the first material so as to permit coulombic interaction between electrons from a first segregated quantum structure to a second segregated quantum structure; and (2) at least two electrodes, each electrode separated from a respective segregated quantum structure by the casing, the casing being sufficiently thin so as to permit coulombic interaction between electrons from the electrode to a respective segregated quantum structure.
It is preferred that each segregated quantum structure has a diameter less than about 200 nanometers. It is more preferred that each segregated quantum structure have a diameter less than about 100 nanometers. It is most preferred that each segregated quantum structure has a diameter less than about 20 nanometers.
It is preferred that the segregated quantum structure comprises a material selected from the group consisting of silicon, germanium, carbon, tin, gallium, arsenic, indium, aluminum, boron, phosphorus, antimony, nitrogen, zinc, sulfur, selenium, tellurium, cadmium, mercury, lead, and mixtures thereof.
It is preferred that the first material comprises a material selected from the group consisting of silicon, germanium, carbon, tin, gallium, arsenic, indium, aluminum, phosphorus, antimony, nitrogen, zinc, sulfur, selenium, tellurium, cadmium, mercury, boron, lead, and mixtures thereof. Alternatively, it is preferred that the first material comprises a semi-conductive material selected from the group consisting of elements of group IIA of the period table, elements of group IIIA of the periodic table, elements of group IVA of the periodic table, elements of group VA of the periodic table, elements of group VIA of the periodic table, and mixtures thereof.
It is preferred that the first material is altered by a process selected from the group consisting of oxidation, reduction, and nitridation.
It is preferred that each electrode comprises a material selected from the group consisting of lithium, beryllium, boron, carbon, nitrogen, oxygen, aluminum, silicon, calcium, titanium, vanadium, manganese, iron, cobalt, nickel, copper, zinc, gallium, germanium, arsenic, yttrium, zirconium, niobium, molybdenum, palladium, silver, cadmium, indium, tin, antimony, barium, tantalum, tungsten, iridium, platinum, gold, mercury, thallium, lead, bismuth, and mixtures thereof.
It is preferred that at least one of the at least two segregated quantum structures is substantially crystalline. It is further preferred that the casing is substantially non-crystalline.
It is preferred that the quantum-dot cellular automata node switch is operational at temperatures in excess of about 2 K. It is more preferred that the quantum-dot cellular automata node switch is operational at temperatures in excess of about 50 K.